I think they mean in the context of your search. This is what has annoyed me most about the "filter bubble" idea. If google doesn't return _relevant_ results, you'll go somewhere else. If I search for a steak restaurant and get results for KFC because, hey, Chicken deserves a chance, that result isn't relevant. If google shows different results for the _same_ query, but both are just a relevant to the searcher, than google is doing its job.